Question

What would be the best (or fastest) way to find all the possible values of ‘foo’ in the following example array.

var table = [     {foo: 0, bar:'htns', stuff:123},     {foo: 2, bar:'snhn', stuff:156},     {foo: 5, bar:'trltw', stuff:45},     {foo: 5, bar:'lrctm', stuff:564},     //few thousand lines later     {foo: 2596, bar:'cns', stuff:321},     {foo: 2597, bar:'gcrl', stuff:741} ]; 

Answer 1

This is a typesafe version of Chetan’s answer:

var result = {}; for(var i = 0; i < table.length; ++i) {     var value = table[i].foo;     result[(typeof value) + ' ' + value] = value; }  for(id in result) {     if(result.hasOwnProperty(id)) {          console.log(result[id]);     } } 

It will still break for objects, though: as long as the toString() method hasn’t been overwritten, they all share the string representation '[object Object]'.